mptcp: move common nospace-pattern to a helper

Paolo noticed that ssk_check_wmem() has same pattern, so add/use
common helper for both places.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 1f52a0fa31ed1544591cbbac4547879da332d715..0413454fcdaf86ff1ddd0ab75285dea669badd62 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -653,6 +653,15 @@ out:
        return ret;
 }
 
+static void mptcp_nospace(struct mptcp_sock *msk, struct socket *sock)
+{
+       clear_bit(MPTCP_SEND_SPACE, &msk->flags);
+       smp_mb__after_atomic(); /* msk->flags is changed by write_space cb */
+
+       /* enables sk->write_space() callbacks */
+       set_bit(SOCK_NOSPACE, &sock->flags);
+}
+
 static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
 {
        struct mptcp_subflow_context *subflow;
@@ -666,13 +675,8 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
                if (!sk_stream_memory_free(ssk)) {
                        struct socket *sock = ssk->sk_socket;
 
-                       if (sock) {
-                               clear_bit(MPTCP_SEND_SPACE, &msk->flags);
-                               smp_mb__after_atomic();
-
-                               /* enables sk->write_space() callbacks */
-                               set_bit(SOCK_NOSPACE, &sock->flags);
-                       }
+                       if (sock)
+                               mptcp_nospace(msk, sock);
 
                        return NULL;
                }
@@ -698,13 +702,8 @@ static void ssk_check_wmem(struct mptcp_sock *msk, struct sock *ssk)
                return;
 
        sock = READ_ONCE(ssk->sk_socket);
-
-       if (sock) {
-               clear_bit(MPTCP_SEND_SPACE, &msk->flags);
-               smp_mb__after_atomic();
-               /* set NOSPACE only after clearing SEND_SPACE flag */
-               set_bit(SOCK_NOSPACE, &sock->flags);
-       }
+       if (sock)
+               mptcp_nospace(msk, sock);
 }
 
 static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)